Who's the fastest???

Quiz time with B. "So," he asks. "Which animal is the fastest in the world?" "The cheetah!" Dad answers immediately. "Wrong!" B replies. "The fastest animal is a bird." "A BIRD?" "Yup. I'll give you a hint," he grants magnanimously. "It starts with a 'p'." "Pigeon?" Dad hazards, frowning because that obviously is not the right answer. "Nope. The peregrine falcon!" B corrects him. "I learned that on 'The Cat in the Hat'." A quick check on the internet reveals that the kid and The Cat are right. Technically. "The peregrine falcon only FALLS the fastest!" "Sure," B allows. "But he falls the fastest on purpose so it still counts as the fastest." Geez. How do you argue with that kind of logic?